Hitherto, there has been known that a power switchgear performs current interruption in a vacuum having excellent interruption performance; and thus, chopping phenomena, which interrupt current when a current value of a circuit decreases to several amperes, are generated and accordingly a switching surge several times as large as circuit voltage is generated due to the chopping phenomena.
Accordingly, in the case where an apparatus, in which there is a concern of insulation deterioration and/or dielectric breakdown due to the switching surge of the power switchgear, is used in a power system, a surge suppression apparatus such as a lightning arrester or a surge absorber is placed between the power switchgear and the electric power apparatus. However, the surge suppression apparatus needs to be placed while securing a sufficient insulation distance to other facility; and accordingly, a problem is that an area of a substation or the like is increased and, in a substation without having a sufficient area, the surge suppression apparatus cannot be placed and thus a problem also exists in that the power switchgear is not adopted.